Received March 24, 2005
Revised May 13, 2005
Accepted after revision June 2, 2005

Micha Kaliszan ¹, Roman Hauser ^1*, Roman Kaliszan ¹, Pawe Wiczling ¹, Janusz Buczyski ², Micha Penkowski ¹

¹ Medical University of Gdask
² Agricultural University of Pozna

^* To whom correspondence should be addressed. E-mail: rohauser{at}amg.gda.pl.

	Abstract

The authors have conducted a systematic study in pigs to verify the models of postmortem body temperature decrease currently employed in forensic medicine. Twenty-four-hour automatic temperature recordings were performed in four body sites starting 1.25 hours after pig killing in an industrial slaughterhouse under typical environmental conditions (19.5 °22.5°C). The animals had been randomly selected under a regular manufacturing process. The temperature decrease time-plots drawn starting 75 minutes after death for the eyeball, the orbit soft tissues, the rectum and muscle tissue were found to fit the single-exponential thermodynamic model originally proposed by H. Rainy in 1868. In view of the actual intersubject variability, the addition of the second exponential term to the model was demonstrated to be statistically insignificant. Therefore, the two-exponential model for death time estimation frequently recommended in the forensic medicine literature, even if theoretically substantiated for individual test cases, provides no advantage as regards the estimation reliability in an actual case. The improvement of the precision of time of death estimation by the reconstruction of an individual curve on the basis of two dead body temperature measurements taken 1 hour apart or taken continuously for a longer time (about 4 hours), has also been proved incorrect. It was demonstrated that the reported increase of precision of time of death estimation due to a multi-exponential model, with individual exponential terms to account for the cooling rate of the specific body sites separately, is artifactual. The results of the study support the use of the eyeball and/or the orbit soft tissues as temperature measuring sites at earlier phases after death. A single-exponential model applied to the eyeball cooling has been shown to provide a most precise death time estimation up to approximately 13 hours after death. For the period that follows, a better time of death estimation is obtained from temperature data collected for the muscles or the rectum.

Key Words: Pathology, Thermoregulation